The stomach and gastric function
Paul Ong, Rachel Skittrall in Gastrointestinal Nursing, 2017
Anatomically, the stomach can be divided into four sections (Figure 4.2): Cardia – The cardia surrounds the superior opening of the stomach and connects to the oesophagus. It contains an abundance of mucus-secreting glands that help protect the stratified squamous epithelial cells of the distal oesophagus.Fundus – The dome-shaped section of the stomach to the left of the abdominal oesophagus is the fundus.Body – Inferior (below) to the fundus is the largest region of the stomach, called the body, and it is here that the bulk of the gastric glands are found that secrete the enzymes and acids.Pylorus – The region that connects the stomach to the duodenum inferiorly at the gastro-duodenal junction is the pylorus. It has two major parts: the pyloric antrum that connects to the body of the stomach and the pyloric canal that joins the duodenum. The pathway of chyme from the pyloric canal to the duodenum is controlled by a thick band of circular muscle called the pyloric sphincter. Glands embedded in the mucosa of the pylorus secrete mucous and digestive hormones that regulate mechanical and chemical digestion.
Infantile hypertrophic pyloric stenosis
Prem Puri in Newborn Surgery, 2017
The human pylorus is characterized by a zone of elevated pressure that relaxes with antral peristalsis, contracts in response to intraduodenal stimulation, and prevents the retrograde movement of duodenal contents into the stomach.47 The hormonal control of the pyloric sphincter function by mediators such as gastrin, somatostatin, cholecystokinin, and secretin has been reported to be the same as in other GI sphincters.48 Since Dodge successfully induced pyloric stenosis by prolonged perinatal maternal stimulation with pentagastrin in approximately one-half of a litter,49 together with the finding of elevated serum gastrin levels in infants with IHPS,50 and growing evidence of strong relation between a gastrin motilin agonist macrolide use and increased incidence of IHPS,17 much attention has been paid to the role of gastrin in the pathogenesis of IHPS. It has been suggested that repeated hyperacid stimulation of the duodenum induced by gastrin evokes repeated pyloric sphincter contractions with work hypertrophy of the pylorus.51 However, Janik et al.52 failed to induce pyloric stenosis in other species by prenatal administration of pentagastrin. Some investigators found significantly high plasma gastrin levels in affected infants compared to healthy controls,50,53 whereas others failed to confirm this finding.54,55 Since raised serum gastrin levels return to normal following pyloromyotomy, it is believed that they are secondary to antral stasis.54
The digestive system
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella in Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
The stomach, located on the left side of the abdominal cavity just below the diaphragm, lies between the esophagus and the small intestine. It is the most distensible portion of the gastrointestinal tract. As with the esophagus, it has a sphincter at either end; the previously mentioned LES is located at the entrance to the stomach and the pyloric sphincter is located at the exit of the stomach leading to the duodenum of the small intestine. The LES is normally closed except during swallowing. The pyloric sphincter is subject to tonic contraction, which keeps it almost, but not completely, closed. In this way, fluids may easily pass through it. The movement of food materials through this sphincter requires strong gastric contractions. Even then, only a few milliliters are pushed through at a time. Gastric contractions mash the food materials and thoroughly mix them with the gastric secretions. This produces a thick, semifluid mixture referred to as chyme.
Comparative study on the gastrointestinal- and immune- regulation functions of Hedysari Radix Paeparata Cum Melle and Astragali Radix Praeparata cum Melle in rats with spleen-qi deficiency, based on fuzzy matter-element analysis
Published in Pharmaceutical Biology, 2022
Yugui Zhang, Jiangtao Niu, Shujuan Zhang, Xinlei Si, Tian-Tian Bian, Hongwei Wu, Donghui Li, Yujing Sun, Jing Jia, Erdan Xin, Xingke Yan, Yuefeng Li
The upper part of the small intestine starts from the pylorus of the stomach, and its lower part is connected with the large intestine via the ileocecal valve, which is divided into duodenum, jejunum and ileum. The HE staining results of duodenum, jejunum and ileum showed obvious injuries in SQD model compared with normal. The main reason may be related to the diarrhoea symptoms of SQD rats. Three parts of the small intestine had more crypt cells, the villi were shortened and indistinct, the villi tips were partially necrotic and detached, the villus epithelial cells were damaged and detached, and edoema was obvious. The intestinal glands were obviously degenerated, and the submucosa was slightly congested and severely oedematous, with a small amount of inflammatory cell infiltration. After treatment, the number, arrangement and morphological structure of glandular cells in each part of the small intestine were significantly improved, the length of villi increased, and edoema was relieved. In particular, HRPCM (18.9 g/kg) and ARPCM (18.9 g/kg) were more significant (Figure 10).
Ascorbic acid-2 glucoside mitigates intestinal damage during pelvic radiotherapy in a rat bladder tumor model
Published in International Journal of Radiation Biology, 2022
Yasutoshi Ito, Tetsuo Yamamoto, Kosuke Miyai, Junya Take, Harry Scherthan, Anna Rommel, Stefan Eder, Konrad Steinestel, Alexis Rump, Matthias Port, Nariyoshi Shinomiya, Manabu Kinoshita
Rats were euthanized with pentobarbital one week after the last X-irradiation fraction, and the bladder and the GI tract were resected. The bladders were inflated with 0.8 mL of 20% formalin and immersed in formalin for two days, followed by paraffin embedding. Slides were prepared from the processed specimens and stained with hematoxylin and eosin (H. E.). The tumor stage was scored according to the TNM classification guidelines (Spiess et al. 2017). The bladder samples were stained with Berlin blue to observe hemosiderin deposits in macrophages. Remained bladder tumors in a rat that died from anesthetic accident during radiotherapy were stained with TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling), using an in situ apoptosis detection kit (MK500, Takara, Tokyo, Japan) as described elsewhere (Ito et al. 2013). Four parts of the small intestine were taken at the 10–15 cm from the pylorus, 25–30 cm, 40–45 cm, and 55–60 cm that was the part at 10–15 cm from the ileocecal valve, and were similarly fixed with formalin, paraffin-embedded, and stained with H. E.
Gastroscopy assisted laser Doppler flowmetry and visible light spectroscopy in patients with chronic mesenteric ischemia
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2019
Simen T. Berge, Nathkai Safi, Asle W. Medhus, Kim Ånonsen, Jon O. Sundhagen, Jonny Hisdal, Syed S. H Kazmi
All patients and controls underwent Gastroscopy Assisted Laser doppler flowmetry and visible light Spectroscopy (GALS) after at least 6 h of fasting. The endoscopic investigation was performed to the horizontal part of the duodenum. Three physicians were present during all endoscopic examinations. All endoscopies were performed by an experienced gastroenterologist and the measurements performed by two vascular surgeons. All measurements were performed by the same team of physicians. Interobserver reliability has been reported to be fair to good for VLS while intraobserver reliability is excellent [12]. The measurement points were chosen carefully, considering the arterial supply of the stomach and duodenum by the branches of the CA and SMA. Two separate measurements were performed at each anatomical site; the horizontal part of duodenum, the descending part of the duodenum, the pylorus and the lesser curvature of the stomach. Furthermore, three points were examined along the greater curvature of the stomach (Figure 1). The mean of the values from each anatomical region was used in the statistics.